MT 15

With the expert help and pro tips of the PRS Forum brotherhood, I was able to achieve the intended operation of the MT15.

Man, nice amp!

First impressions after a brief playthrough - it is, indeed, LOUD. And it keeps a nice thump as it gets turned up. Haven't had a chance to really let it wide open for more than a quick volume check, but even at 9 o'clock on the lead channel master, it is brain punishing loud.

Tones - very, very nice. I hear the PRS amp lineage in it for sure, which is cool. Hard to get an ice-pick sound, plenty of bass in 15w mode, and lots of midrange available too, which is similar to my Custom 50. Tighter on the bottom, as one would expect from this amp. With the half power switch on, the volume doesn't change much, it's a tonal difference - the bottom is still punchy, but not as big and ominous, which makes the mids pop and bark more. If you were in a pinch and needed to pass for a vintage Marshall sound, going to half power and bumping the mids up would do great for cover tunes. The clean channel is a lot like the Custom 50, has some sparkle but not overly bright like a Deluxe, etc., and the pedals that work well with the Custom also work well with the MT15. Although I think the mid sweep may be wider on the MT15, and I had to bump them up more on the clean to get it sounding right with drive pedals. On both channels, perhaps the mids are more focused/tuned to a certain frequency band on the MT15, and can be dialed out more if desired. The Custom has a more broad, sweet midrange, if that makes sense.

I've heard some people comment on how light it is, and I guess I would put an asterisk on that and say that, for an amp head in general, yes, but for a "lunchbox" amp, it's actually kinda hefty. Which is right where I would want it, heavy enough to know there's some serious iron in there, but still easy to tow around. Comes with a high quality soft carry case too, a nice touch.

My only gripe so far is that it has some loud hiss here and there - unexpectedly, with the gain down very low, or off altogether, on the lead channel, there's an almost rippling or stuttering sound, kinda odd and annoying, but as the gain increased, the cascading white noise that all gain monsters have covers it up, and you certainly don't hear it when playing. And, of course, there's just a lot of hiss on the lead channel because of the numerous gain stages - but I always use a noise suppressor in my loop to squash that, so I'm not too worried. On the clean channel, there's also some odd hiss when the volume is below 9:00, on that channel that's late night bedroom level, so normal play wouldn't be affected. It's just odd to hear that noise actually get quieter as the volume is turned up. I think there's something in the power section at work on both channels causing that, because the preamp doesn't seem to affect the low volume hiss. And aside from that normal high gain hiss, the other phenomenon aren't present at normal play volumes, so they shouldn't be a big issue.

I'm taking it to play through my 2x12 on Tuesday night with a loud drummer, so we'll see how it holds up where I would normally play the Custom 50. I can already hear some more midrange popping up from the 6L6's, so I'm interested to hear how that translates. There's a very obvious step up in tonal refinement over what my old SE amp had, nice to see PRS has this import game dialed in. Heck of a lot of amp packed into this little box and small price tag!
 
Mine is whisper quiet. I had to unplug my pedal board, though. Ground loop, or something, caused a huge amount of buzz. I haven't taken the time to dig into it yet.

Were you using the effects loop? If so, I'm having the same experience.

Edit: Actually, happening with or without the loop.
 
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Were you using the effects loop? If so, I'm having the same experience.

Edit: Actually, happening with or without the loop.

No, I was running in front. Ordered a new pedal last week. Board is torn apart at the moment. Hope it's better when I reassemble.
 
Actually had to come back.....this means you snagged one?

Yep! The local shop has a sister online site, and I could see thy had one in the warehouse... called to see if they had one in store and they had just unpacked it before I called, so I had them hold it for me. Feel like I won the lottery, lots of pre orders are still a while out!

I'm gonna go dilly dally with mine again this evening. I didn't have a problem running my board all into the front end, but when I split the time based effects into the loop and drives in front, it hums like a bad ground connection. Strangely enough, only when the guitar input is plugged in from the drive pedals. Loop plugged or unplugged, on its own, makes no difference. I have "kinda isolated" power on my board, the drive pedals are on a daisy chain, wondering if that has something to do with it. Also, when the lead channel gain is at 0, it has another sound like a bad ground connection. It's still present as the gain is increased, but the hiss from the gain stages (normal) covers it up.

If I can get the board grounding issue settled, my noise gate will mute that latter sound - and I will be using the gate, there's just too much white noise not to, which isn't a dig against the amp, it's just the way high gain amps are. The problem right now is that the gate will cover one hum, but my board adds the other, which defeats the purpose. I don't know if it's a problem with grounding in the amp, power in my house, or just the way it is with so much cascaded gain. I've never had a similar problem with my other high gain amps on the same plugs in my house though. If it is the amp, and PRS can trace it to one specific thing, I would love to just fix it with the ol soldering iron rather than spend money shipping and their time fixing.
 
Yep! The local shop has a sister online site, and I could see thy had one in the warehouse... called to see if they had one in store and they had just unpacked it before I called, so I had them hold it for me. Feel like I won the lottery, lots of pre orders are still a while out!

I'm gonna go dilly dally with mine again this evening. I didn't have a problem running my board all into the front end, but when I split the time based effects into the loop and drives in front, it hums like a bad ground connection. Strangely enough, only when the guitar input is plugged in from the drive pedals. Loop plugged or unplugged, on its own, makes no difference. I have "kinda isolated" power on my board, the drive pedals are on a daisy chain, wondering if that has something to do with it. Also, when the lead channel gain is at 0, it has another sound like a bad ground connection. It's still present as the gain is increased, but the hiss from the gain stages (normal) covers it up.

If I can get the board grounding issue settled, my noise gate will mute that latter sound - and I will be using the gate, there's just too much white noise not to, which isn't a dig against the amp, it's just the way high gain amps are. The problem right now is that the gate will cover one hum, but my board adds the other, which defeats the purpose. I don't know if it's a problem with grounding in the amp, power in my house, or just the way it is with so much cascaded gain. I've never had a similar problem with my other high gain amps on the same plugs in my house though. If it is the amp, and PRS can trace it to one specific thing, I would love to just fix it with the ol soldering iron rather than spend money shipping and their time fixing.

Pedals will hum unless isolated, to one degree or another. Daisy chaining pedals is problematic. Time for a proper power supply.
 
Man, if you have the chance to turn it up a bit - say up to the midway point on the master volume - I'd be REALLY interested to see what the dB measurement is at that point!

So I played around with this yesterday. I did a video to post on Instagram, but it's 4 minutes and Instagram only does a minute. After re-reading this, I know how I'm going to trim the video - I'll show you from around 10:00 on the master volume and bumping up from there.

The short version? LOUD. I hit 110 db with the gain around 10:30 on the knob and the master volume around 11:00. As the master went up from there, I got to about 112-113 db, then it just seemed to compress more. It's pretty frigging impressive.

Instagram link later tonight.
 
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